Abstract

The opacity of a goldplasma at the temperature of 85 eV and density of 0.02 g/cm3 was measured over the energy range from 150 eV to 1200 eV. The gold sample was heated by thermal x-ray radiation generated with a foam-baffled gold cavity. The sample transmission was obtained from the backlight, absorption and self-emission spectrameasured by a time-gated, spatially resolved grating spectrometer, with the backlight and absorption spectra being measured simultaneously in a single shot and the self-emission in another shot. The temperature and density of the gold absorber were determined by the hydrodynamic simulation with Multi-1D code, which was partially tested by the reemission radiative flux measurements of the heated sample. This work permits the first test of opacity models over the photon energy range that dominates the Rosseland mean opacity at the temperature of interest for the inertial confinement fusion.

The authors would like to thank the target fabrication, the laser operation, and the experiment diagnostics staffs for co-operation, and this work was performed under the auspices of the National Nature Science Fund of China (Grant No. 10875109) and the Fund of State Key Laboratory Interaction with Matter (Grant No. SKLLIM0903).